Injury/ Trauma

1. Injury/ Trauma • Injury occurs when local stress or strain exceeds the ultimate strength of bones and/ or soft tissues. • The rate of injury or tissue deformation also contributes to the degree of injury

2. Trauma/ Injury • An injury includes mechanical failure and destruction of the cells and tissues.

3. The Phases of Healing • There are 3 phases of healing: • Acute Inflammatory Response • The Proliferation Phase • The Maturation Phase

4. Acute Inflammatory Response • Mechanical trauma, such as a sprain, strain, disc injury, amputation or burn, results in damaged cells; • Damaged cells initiate the inflammatory response; • The sudden and extended release of inflammatory mediators is necessary to initiate the healing response.

5. The Inflammatory Response • The inflammatory response: • Attracts precursors for cell growth, and • Encourages repair mechanisms. • The buildup of fluids causes chemical irritation and mechanical pressure on the nerve receptors. • Chemical irritation and mechanical pressure stimulates pain receptors, which serve a protective purpose, causing patients to limit motion around the damaged tissue.

6. The Inflammatory Response • Other effects of the inflammatory response include: • Clogging of the vasculature which results in further cell death due to cell oxygen deprivation; • Muscle spasm occurs due to the pain and lack of oxygen, and • The patient moves less due to pain and muscle spasm.

7. Inflammation • Necessary part of the healing process • However, if the inflammatory response is prolonged or particularly intense, it may lead to chronic inflammation which can be debilitating • Through use of therapeutic modalities, we can influence the inflammatory response promote healing

8. Cardinal Signs of Inflammation • Heat • Redness • Swelling • Pain • Loss of Function

9. Measuring Inflammation • Measure the amount of swelling compared to the opp0site side • Point tenderness on palpation • Joint range of motion as compared to the opposite side

10. Typical Presentation in Acute Inflammatory Response Phase • Swelling • Loss of Range of Motion • Muscle guarding • Splinting postures

11. Duration of the Acute Inflammatory Response • Begins immediately following injury • Persists until the stimulus is removed/ mediators dissipated • May last a few seconds or a few months

12. Proliferation Phase • The number and size of fibroblasts increase allowing for the collection of ground substance and collagen to collect in preparation for tissue repair. • Growth of new tissue • Development of new blood vessels • Development of fibrous tissue • Wound contraction • Formation of collagen matrix

13. Proliferation Phase • Removal of debris and temporary repair tissue formed by the inflammatory response phase • Development of new, permanent replacement tissues • Development of new vascular framework to supply repairing tissues with oxygen and nutrients and cells needed to restore the area

14. Proliferation Phase • Thought to begin approximately 72 hours after injury • May last 3 weeks

15. Maturation Phase • Collagen and Fibroblasts attempt to align themselves in the original tissue orientation, although this does not always occur. • Main focus is: • Deposition of permanent tissues • Return to normal function

16. The Injury Response Trauma Ischemia Cell Death Contain Injury Secondary Trauma Inflammation Phagocytosis Clogging of Blood Flow Bleeding Swelling Blood Clotting Revascularization Pain, spasm, atrophy Wound Contraction Tissue Repair Loss of Function Wound Remodeling Return to normal function